It is becoming increasingly clear that cellular behavior is dictated by complex networks. Transcriptional regulation of genes plays a dominant though not exclusive role in the regulation of such networks. The founding premise of this new Shared Resource is that a large number of JCCC investigators need reliable and economical means by which to monitor such transcriptional networks. At this time, microarray analysis provides the most efficient means for quantitatively assaying the expression of a large number of genes in a cell simultaneously. The Gene Expression Shared Resource provides assistance or actual performance at every step of a microarray expression experiment. Both cDNA (spotted) and oligonucleotide (Affymetrix) microarray services are offered through the GEC, as well as custom printing services and educational services. The GEC also provides a database service to store and organize microarray data and information regarding experiments performed on microarrays. By virtue of providing a universal means for data collection, retrieval and analysis, the GEC serves to optimize investigators? interactions regarding microarray experimentation in the JCCC.